• Thanasimus formicarius (L.);
  • life cycle;
  • bionomics

Abstract  Observations on the life cycle and bionomics of Thanasimus formicarius (L.) were made under natural conditions and in the laboratory. The studies provide information on mass flight, development periods of eggs, larvae, pupae and prepupae, and adult maturation stage based on monthly field investigations. The results of the research suggest that the overall life cycle of T. formicarius covers approximately two years and four months in southern Norway. During the first year of the life cycle, the clerid larvae overwinter in the pupal chambers at the bases of attacked spruce trees; adults emerge and mature sexually in the second year; and the mature adults overwinter inside the bark crevices of trunk and oviposit in the spring of the third year. The studies also expose that the clerid occurence coincides well with the bark beetle attacks occurring in spring and autumn in northern Norway.